The remnant natural boreal forest green belt of the Scandinavian mountain range

Abstract

To meet environmental goals and principles of sustainable forest and landscape management, arguments and knowledge accumulate on the need to increase forest protection and expanding restoration and conservation-oriented management. Certain attention has been given to regions where large, contagious natural forest areas still remain, and to interior forest core areas that due to distance to edge disturbance have developed continuity characteristics. A general assumption is that large continuity areas contain highly valuable ecosystem attributes that should be preserved per se, but also to spread into the surrounding forest landscape. In this study we analyzed the structural and functional connectivity of boreal continuity forests. We analyzed a comprehensive data set consisting of a remote sensing-based chronosequence mapping covering 11.7 million ha of the boreal biome in Sweden, where forests in that have not been subject to harvesting during the last 60-70 years have been identified. This data represents a high-resolution, complete and consistent trajectory of remnant forest patches that broadly covers the most intensive, industrial forest management era. Our study objectives were to analyze the structural and functional connectivity characteristics, to assess the center to periphery and matrix relationships for interior forest core areas, and to define existing larger, connected components of remaining natural forest as landscape-level hotspots for a functional green infrastructure. Through density and network analyses we defined a “green belt” consisting of connected natural and near-natural forest south-to-north along the foothills zone of the Scandinavian mountain range. We also found a more or less completely disrupted connection west-to-east with a few isolated components in the inland and coastal areas. The forest land area outside the components represent a peripheral matrix where continuity values are lost but where directed restoration and adapted forest management should be directed to support the ecological functionality of protected forests.